Method and apparatus for shrinking woven or knitted textile fabrics



HZ 1mm v A, HEINE 2,144,151

METHOD AND APHWATUS FOR SHRINKING WOVEN OR KNITTED TEXTILE FABRICS FiledOct. 5, 1934 2 Sheets-Sheet 1 v 2a 30 I Q iv Q zff Jan. 17, W39. 7 A. HEINEN I METHOD AND APPARA'IAH t'OH SHRINKING WOVEN 0R KNITTED TEXTILE FABRICS Filed Oct. 5, 1954 2 Sheets-Sheet 2 Patented Jan. 17, 1939 .umrso STATES PATENT OFFICE METHOD AND APPARATUS FOR SHBINKING WOVEN R KNITTED TEXTILE FABRICS Andreas Heinen, Cologne, Germany Application touching the fabric. This process requires a covering of the other side of the fabric also. Therefore the threads have no possibility tobalance' their inner tensions voluntarily. However the yarns and also the weaves in the textile fabrics are not so perfectly even that (by applying a mechanical treatment being absolutely the-same for all parts of the fabric) it could be expected to get rid of all inner tensions caused during the finishing processes, as it is the case in the washing process where the fabrics have every possibility to balance all tensions.

The invention however gives to all particles of the fabric this possibility by'giving to the soaked threads (soaked for instance by the known steaming process) the impulse for balancing the tensions by a short but effective pushing, The fabric is fixed in the balanced state by drying, in a manner that the particles of the fabric have still to some extent the possibility to balance ten sions. The shrinkage itself is obtained according to the invention by fixing the fabric to the conveying means (particularly to perforated drums) only by diiference in air pressure produced either by positive air pressure on the outer side or negative air pressure on the inner side of the conveying means, pushing it together at the place where it moves from one to the other drum, in a manner' that the first conveying means is faster 'driven than the second one. Because the fabric, treated in such manner, reaches the slower running conveying means with loosened weave and is held on this means point for point on account of the suction pressure, it is possible to balance the tensions up to the moment when the fab ric is perfectly dry.

Forflxing the fabric reliably (after pushing it together) to the drum running at lower speed. it is proposed according to the invention to keep the difference in pressure acting on this drum higher than the diilerence in pressure of the drum running at higher speed. v

This machine being extraordinarily suitable for this process is of similar construction to the known suction drums used for warp, but is completed by such means which allow an from drum 2 can be regulated in the direction of are provided inside or outside October 5, 1934, serial No. 741,007 In Germany October 6, 1933 6 Claims. ((31. 26-185) variable speed transmission to each drum and drum cylinder, respectively, and which allow an exact regulation of the distance of the cylinders at the place where the fabric moves from one drumto the other.v 5

.In the accompanying drawings:-

Fig. 1 is a diagram in elevation of one form of apparatus upon which the method or art may be carried out.

Fig. 2, 3, 4, 5 are diagrams ofv other forms of 1c apparatus for the same purpose.

Fig. 6 is the front elevation of a machine for practising said process.

Fig. 7 is a plan corresponding to Fig. 6.

Flg 8 is a 'detail vertical section employed.

For carrying through the idea of the invention as shown on Figs 1, 2, 6, 'l, 8, two drums i, 2 are arranged, oneabove the other, in a manner that they may come into contact with each other at the mark 2. The distance of the upper drum l the arrow X.

' In front and behind the drums there are arranged means for stretching and guiding, in a manner that the fabric goes round the drums in js-form as known in cylinder drying machines.

The cylinders of the drums are perforated, and the placeswhich are not covered by the fabric with the usual cover-plates 8, 8, iii. In view of the fact that the hollow spaces 1, 9 which are produced by the inside covering show the same pressure as the outside air, they assist the loosening and trans- -ferring of the fabric 3 from one drum to the other. 85

The drive of both drums has to be provided in a way that the peripheral speed of each drum may be regulated independently of each other.

In Figs. 6 to 8 the diameterof the lower drum is considerably larger than the diameter of the upper drum l. The upper drum has aflne reg ulating device for moving the drum in the direction of the arrow a: upwards or downwards. On both sides of the drums which are covered with screens Fig. '1 there are arranged fans It, It, l8, l1 sucking air through the fabric and screens into the inner portion of the drum. For this purpose the side walls of the drums 26 have openings. At the entrance oi the machine. at least two rollers II with automatically adjustable speed are arranged Moreover are arranged in ifront spraying pipes l2 and steaming pipes ii, in a manner that the fabric if required can be moistened or steamed-or warmed. The drums and ,the feeding rollers are dnventhrough a speed Ill regulating device [8, by means of chains 19, 20, 2|. The fans have belt drive 22, 220, but in such a manner that the speed of the fans and therefore the suction in each drum can be regulated independently of each other. Finally the lower drum 2 is equipped with drying means, consisting in the present case of a number of perforated pipes 46 which receive hot air from a ring main 45. A fan 24 is forcing hot air from a heater 23 into the main ring 45.

Fig. 3 shows in the place of the lower drum 2 a conveying belt 29, also driven at adjustable speed and guided over the guide rollers 3| and suction box 28. The cover-plate 30 corresponds with the plates I0 of Fig. 2.

Fig. 4 shows in the place of both drums conveying belts 36, 31 which are guided over guide rollers 32, 33 and driven at different speeds and over suction boxes with curved perforated surfaces 34, 35 and with cover-plates 38, ina manner that the fabric may go over from the conveying belt running at the higher speed to the belt running at the lower speed, at the place where the belts are closest together (arrow 2) If this line is displaced in consequence of the thickness or sagging of the conveying belts, the cover-plates 38 will be adjusted accordingly.

Fig. 5 shows the conveying belts 43, 44 running over suction boxes with fiat surface 4|, 42,' also guided by guide rollers 39, 40. In this case the distance between the two conveying belts will be adjusted by moving the suction boxes to or from each other, so that the acting edges of the boxes are in the same vertical line. No special protection is required for the construction according to Figs. 3, 4, 5.

The operation is in general the same with all these constructions and may therefore be particularized at the machine according to Figs. 6 to 8. The woven or knitted fabric 3 is taken by the feeding rollers H from a pile or from a finishing machine or from a set of such machines arranged in front. Then the fabric is moved to the upper drum l, directly or after having been moistened, steamed or warmed according to its inner elasticity, moisture content and filling. With those fabrics which show the tendency of shrinking already before arriving at the drum I and which should shrink in the direction of the warp, the speed of the feeding rollers must be increased accordingly, and if they should shrink in the direction of the weft, the speed of said rollers must be reduced accordingly. The fabric remains for a certain time in the same state as it comes to the upper drum I (the upper conveying means), because it is pressed on to thesurface of the drum by means of the suction effect. The fans l4, [5 are so adjusted that the produced suction will be just sufficient to hold the fabric 3 firmly to the drum l. p

The suction of the lower drum 2 (the second conveying means) which in general is to be higher than for the first conveying means, and the degree of the reduced speed of drum 2- are to be adjusted according to the kind. of fabric and moisture contents. If for instance it is shown with the pre-test (washing test) that the warp of the fabric has shrunk by 6 per cent, the advanced speed of the upper drum I, compared to the lower drum 2, must be adjusted in the proportion of 100/94. If necessary; hot air is to be fed in, temporarily or continuously, by the fan 24,

'drum 2.

in order to be sure that the fabric will dry on is plaited or fed into the finishing machines, if

When leaving the machine, the fabricnecessary after having it passed through a cooling and moistening arrangement.

Chief attention is tobe given to the fabric at the moment when passing from one drum (one conveying means) to the other. As the distance of the conveying means must correspond with thethickness of the fabric, particular care is to be taken that if any swelling of the fabric should occur, the fabric does not come under the effect of squeezing pressure.

When adjusting the advanced speed it will perhaps be necessary to balance any tension being produced in the fabric by the other preceeding finishing processes as it is usual in the shrinking of the fabrics.

What I claim is:-

1. Method of shrinking Woven or knitted textile fabrics comprising applying the fabric to the surface of a traveling support, subjecting the fabric while on the support to the action of air pressure for causing it to adhere to support surface, imparting to this support an advance movement at a predetermined speed, transferring the fabric from the said support to another support spaced from but in close succession to the former, subjecting the fabric on the last-said support to the action of air pressure higher than that used on the first-said support for causing the fabric to be afiixed to the surface of the last-said support more firmly than to the first-said support, imparting to the last-said support an advance movement at a speed lower than that of the first-said support, thereby to produce a compression of the fabric parallel to its surfaces in the gap between the two supports.

2. Apparatus for shrinking woven or knitted textile fabrics, comprising at least two successively arranged closely spaced endless conveyors over which to pass the fabric, means for producing air pressure at the first conveyor whereby to hold the fabric on this conveyor, means for producing air pressureat the second conveyor higher than at the first whereby to afiix the fabric more firmly on the second than on the first conveyor, and means for driving the first conveyor faster than the second. a

3. Apparatus for shrinking woven or knitted textile fabrics, comprising at least two perforated drums arranged in close succession to each other at an adjustable distance and designed to have the fabric passed over them, means for creating negative pressure in the interior of the first drum whereby to hold the fabric firmly on this drum, means for creating in the interior of the second drum a negative pressure higher than in the first whereby to aflix'the fabric more firmly on the second than on the first drum, and means for rotating the first drum faster than the second. 4. Apparatus for shrinking woven or knitted textile fabrics, comprising at least two perforated drums arranged in close succession to each other at an adjustable distance and designed to have the fabric passed over them, fans at the ends of the first drum for creating in the interior there of a predetermined negative pressure whereby to hold the fabric firmly on this drum, fans at, the ends of the seconddrum for creating in the interior thereof a negative pressure higher than in the first drum whereby to afllx and hold the fabric more firmly on the second than on the first drum, and means for rotating the first drum faster than the second drum.

5. Apparatus for shrinking woven or knitted textile fabrics, comprising at least two perforated drums arranged in close succession to each other of a predetermined negative pressure whereby to hold the fabric firmly on this drum, fans at the ends of the second drum for creating in the interior thereof a negative pressure higher than in the first drum whereby to affix and hold the fabric more firmly on the second than on the first drum, means for rotating the first drum faster than the second drum, and hot air nozzles around the circumference of the second drum whereby to direct hot air to the fabric on this drum for drying the fabric.

6. Apparatus for shrinking woven or knitted fabrics, comprising at least two successively arranged endless conveyors permeable to air over which to pass the fabric, mean for producing a difference of air pressure between the inner and means for driving the first conveyor faster than the second.

' ANDREAS HEINEN. 

